| /** |
| * Copyright 2010 The Apache Software Foundation |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hbase.util; |
| |
| import org.apache.hadoop.hbase.HRegionInfo; |
| import org.apache.hadoop.io.DataInputBuffer; |
| import org.apache.hadoop.io.Writable; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.io.DataInputStream; |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| |
| /** |
| * Utility class with methods for manipulating Writable objects |
| */ |
| public class Writables { |
| /** |
| * @param w writable |
| * @return The bytes of <code>w</code> gotten by running its |
| * {@link Writable#write(java.io.DataOutput)} method. |
| * @throws IOException e |
| * @see #getWritable(byte[], Writable) |
| */ |
| public static byte [] getBytes(final Writable w) throws IOException { |
| if (w == null) { |
| throw new IllegalArgumentException("Writable cannot be null"); |
| } |
| ByteArrayOutputStream byteStream = new ByteArrayOutputStream(); |
| DataOutputStream out = new DataOutputStream(byteStream); |
| try { |
| w.write(out); |
| out.close(); |
| out = null; |
| return byteStream.toByteArray(); |
| } finally { |
| if (out != null) { |
| out.close(); |
| } |
| } |
| } |
| |
| /** |
| * Set bytes into the passed Writable by calling its |
| * {@link Writable#readFields(java.io.DataInput)}. |
| * @param bytes serialized bytes |
| * @param w An empty Writable (usually made by calling the null-arg |
| * constructor). |
| * @return The passed Writable after its readFields has been called fed |
| * by the passed <code>bytes</code> array or IllegalArgumentException |
| * if passed null or an empty <code>bytes</code> array. |
| * @throws IOException e |
| * @throws IllegalArgumentException |
| */ |
| public static Writable getWritable(final byte [] bytes, final Writable w) |
| throws IOException { |
| return getWritable(bytes, 0, bytes.length, w); |
| } |
| |
| /** |
| * Set bytes into the passed Writable by calling its |
| * {@link Writable#readFields(java.io.DataInput)}. |
| * @param bytes serialized bytes |
| * @param offset offset into array |
| * @param length length of data |
| * @param w An empty Writable (usually made by calling the null-arg |
| * constructor). |
| * @return The passed Writable after its readFields has been called fed |
| * by the passed <code>bytes</code> array or IllegalArgumentException |
| * if passed null or an empty <code>bytes</code> array. |
| * @throws IOException e |
| * @throws IllegalArgumentException |
| */ |
| public static Writable getWritable(final byte [] bytes, final int offset, |
| final int length, final Writable w) |
| throws IOException { |
| if (bytes == null || length <=0) { |
| throw new IllegalArgumentException("Can't build a writable with empty " + |
| "bytes array"); |
| } |
| if (w == null) { |
| throw new IllegalArgumentException("Writable cannot be null"); |
| } |
| DataInputBuffer in = new DataInputBuffer(); |
| try { |
| in.reset(bytes, offset, length); |
| w.readFields(in); |
| return w; |
| } finally { |
| in.close(); |
| } |
| } |
| |
| /** |
| * @param bytes serialized bytes |
| * @return A HRegionInfo instance built out of passed <code>bytes</code>. |
| * @throws IOException e |
| */ |
| public static HRegionInfo getHRegionInfo(final byte [] bytes) |
| throws IOException { |
| return (HRegionInfo)getWritable(bytes, new HRegionInfo()); |
| } |
| |
| /** |
| * @param bytes serialized bytes |
| * @return A HRegionInfo instance built out of passed <code>bytes</code> |
| * or <code>null</code> if passed bytes are null or an empty array. |
| * @throws IOException e |
| */ |
| public static HRegionInfo getHRegionInfoOrNull(final byte [] bytes) |
| throws IOException { |
| return (bytes == null || bytes.length <= 0)? |
| null : getHRegionInfo(bytes); |
| } |
| |
| /** |
| * Copy one Writable to another. Copies bytes using data streams. |
| * @param src Source Writable |
| * @param tgt Target Writable |
| * @return The target Writable. |
| * @throws IOException e |
| */ |
| public static Writable copyWritable(final Writable src, final Writable tgt) |
| throws IOException { |
| return copyWritable(getBytes(src), tgt); |
| } |
| |
| /** |
| * Copy one Writable to another. Copies bytes using data streams. |
| * @param bytes Source Writable |
| * @param tgt Target Writable |
| * @return The target Writable. |
| * @throws IOException e |
| */ |
| public static Writable copyWritable(final byte [] bytes, final Writable tgt) |
| throws IOException { |
| DataInputStream dis = new DataInputStream(new ByteArrayInputStream(bytes)); |
| try { |
| tgt.readFields(dis); |
| } finally { |
| dis.close(); |
| } |
| return tgt; |
| } |
| } |